The present invention relates to a method for limbing, barking and chipping logs in a preferably mobile unit, and a device for utilization of the method.
For example, a previously known device is disclosed in U.S. Pat. No. 3,653,417 for removal of limbs and debarking, including a barking unit having a number of pivotally attached barking knives, each one being associated with an hydraulic cylinder by means of which the barking knives can be pressed against a log, and also including a conical member supporting a number of cutters, which when rotated act as a milling cutter, and thus cuts or mills away existing branches from the log. This device is located in an intermediate position between two conveyor belts, which are used to impose a linear movement for the log through the device. A further example of a previously known device is disclosed in SE Patent No. 398 612, intended to remove branches from a log, and chip the removed branches. The log is fed with the larger end portion as a first end portion, and the branches are pressed in direction towards the top of the log and removed, whereafter the branches by means of a conveyor belt are moved to a chipper. It is also proposed that the top of the log is cut off, and moved together with the branches to the chipper. Limbing and barking of the log is performed by means of a rotary limb removing drum, at one end portion having limb cutting and bark removing means peripherally arranged, which by means of a strong rubber band or similar means are pressed against the peripheral portion of the log. These previously known devices are not suitable when, for example, logging in small-tree forests, as when performing thinning, and when relatively small diameter logs are to be transformed into chips.